Rotary switch beater ejector

ABSTRACT

A food mixer speed control rotary switch and beater ejector unit in which a multi-speed permutation rotor for switching multiple field coil windings is journalled on a plastic frame that supports axially spaced spring switch blades bearing radially on the rotor and a beater ejection push rod is coaxially disposed therewith for the mutual support of each other in a readily assembled unit that includes a nested push button and dial assembly recessed protectively in the forward post of the food mixer handle. The shaft of the dial is journalled in the handle and supports the upper ends of the rotor and ejector rod for thumb operation selectively and simultaneously. Some of said spring switch blades are in open, stressed engagement with said rotor at any given time to hold the rotor in said journalling means.

ton and dial assembly recessed protectively in the for- 1 51 Apr. 3, 1973 FOREIGN PATENTS OR APPLICATIONS Robe" Emmfins, Collinsville, 644,197 10 1950 Great Britain.,....................200/6 BB Conn.

Assignee: Dynamics Corporation of America, Primary Schaffer New York, Assistant Examiner-Robert A. Vanderhye Feb. 1971 Attorneyl-larbaugh & Thomas Appl. No.: 117,654 [57] ABSTRACT A food mixer speed control rotary switch and beater .200/157, 200/153 LB, 259/1 A, ejector unit in which a multi-speed permutation rotor 310/68 A for switching multiple field coil windings is journalled HI.-

n a plastic frame that upports axially spaced pring [58] Field of Search..........200/4, 157, 153 LB, 6 BB, Switch blades bearing radially on the rotor and a 6185;339/95 95 D; 310/68 50; A beater ejection push rod is coaxially disposed therewith for the mutual support of each other in a References Cited readily assembled unit that includes a nested push but- UNITED STATES PATENTS ward post of the food mixer handle. The shaft of the dial is journalled in the handle and su United States ateritt [191 Emmons 54] ROTARY SWITCH HEATER EJEC'IOR [75] Inventor:

22 Filed:

52 u.s.c1...........

13 Claims, 8 Drawing Figures ends of the rotor and ejector rod for thumb o selectively and simultaneously. Some of sa switch blades are in open, stressed en rotor at any given time to hold the rotor in said 2 S- 3 n v a t 6 m 2. ll n o H O 9 l l 9 a a 4 m 3. Mn I l/ 0 I 8: 2 I m 5 W li I W M XXXAMDXA n 1 .1 BBB B I LBLWNBLW .1 MN 363 3 I ll 2 3 2 I 0.1 31 I /0/ u I l 020. "0 Ill 0 0 ."O 8 2 m2 m2 9 Gresens eta] m m mu m mm h 0 6 an yWmd 1... rh 1 u-lt 3 l 1 6 m HwAGRws 63060579 65657656 99999999 11111111 86 32035 1 1 820 6255 6879209 4 0 5 3 6 7 9 7 44073463 64639 84 ov a dw 32223323 PATENTEUAPRB 1975 3 5,5 4

SHEET 1 OF 2 I/VVE/VTOI? ROBERT J. EMMONS PATENTEDAPRS I973 I v ZA SHEET 2 BF 2 ROBERT J. EMMONS frorneys ROTARY SWITCH BEATER EJECTOR,

CROSS REFERENCES Swanke et al., Ser. No. 636,457, now U.S. Pat. No. 3,493,833.

Swanke et a1., Ser. No. 813,957, now U.S. Pat. No. 3,596,161.

Swanke and Conlon, Ser. No. 26,967, now U.S. Pat. No. 3,627,937.

BACKGROUND OF THE INVENTION In many household appliances where a wide range of speeds is desired, as in a food mixer, versatility and miniaturization of the switching mechanism is desirable from a space availability viewpoint since hi-power and low weight are rivalling factors. Also, it is quite important for safety and convenience with a hand supported mixer that all of the important controls be located for thumb operation while the fingers are supporting the weight or manipulating the power unit.

SUMMARY OF THE INVENTION Two of the most important items in a portable food mixer are the switch and a beater ejector. Both are provided in the present invention and are combined in a very compact unit. Availability of a large number of speeds for directions in recipes is also important along Thereby the rotor-switch coaction and parts are greatly simplified and the diversity of inventory is minimized to include a frame, rotor, switch blade and a blade retainer comb. The switch blades are identical,

all comprise a V-shaped detent bend in the middle of with being able to set the mixer down with the heaters overhanging a drip dish, and these are also provided to afford the user with the greatest convenience and freedom from confusion possible along with finger tip control.

A compact unit of an ejector and speed switch that is receivable in the front pillar of the handle provides for lightness and the power unit housing can be of a size closely dimensioned to the overall shape and size of the motor and gearing assembly. Although the construction shown in said Swanke and Conlon, Ser. No. 26,967, of a like switch, shows how 16 speeds can be provided for an appliance, the invention as described in this embodiment shows the versatility thereof as related to at least six speeds with a double acting rotor.

The switch is elongated approximately the height of the handle and is provided with support arms holding the switch in a vertical position in the front pillar of the handle above the level of the motor and beater transmission. In this relationship it is protectively supported and its control knob is immediately available for operation at thumb level in a recess at the top of the handle. The vertical portion of the light push rod reinforces the rotor against flexing as well as strengthening it to carry the pressure of normally closed spring switches bearing thereagainst whose size and smallness exert a greater effective effort upon the rotor than if they were longer spring switch blades. Furthermore, with this arrangement a comparatively small diameter rotor can be provided and still be used to actuate the spring switch blades engaging it as well as being locked in place by the electrical connections soldered thereto.

Moreover, the springs operate as actuated by the rotor, to hold the rotor firmly in operative position with respect to the supporting bearings on the switch housing so that coaction tolerances between coacting parts can be easily held quite close to prevent any possible simultaneous closure of tapped field coil switches that might short one of the field coil sections.

the moveable conductor portion which serves also as a speed selection locating detent engaging in cam recesses staggered around the rotor so that each switch is closed and opened while the others are held open. Where the speed selection includes the use of a diode, the rotor provides two cam recesses for selected switches, one a long cam recess for operation of the diode switch in association with certain separately selected speed switch closings, is employed to double the available speeds provided otherwise by the coil control switches. The switch construction enables the miniaturization of parts and assembly which enables permanent snap-in assembly of the switches and rotor for readily consummated riveting or wave soldering of plastic parts and the ready insertion of pushin circuit wire connectors for each switch blade.

IN THE DRAWINGS FIG. 1 is a perspective view of the front end portion of a food mixer embodying the invention;

FIG. 2 is an enlarged sectional portion taken on line 2-2 in FIG. 1;

1 FIG. 3 is a sectional view taken on line 3-3 of FIG.

FIG. 4 is an enlarged perspective view of the switchejector unit;

FIGS. 5, 6 and 7 are sections taken on lines 5--5, 6- 6 and 7-7, respectively, in FIG. 4;

FIG. 8 is a schematic electrical circuit illustrating the motor speed control parameters attained.

EMBODIMENT OF INVENTION:

Referring to FIG. 1, the food mixer embodying the invention has a housing 10 enclosing the working parts and includes a handle 12 supporting the power unit 14 in the upper housing portion 16 by means of fore and aft vertical pillars 18 and 20 integrally interconnecting the handle 12 and lower portion 16. The power unit 14 supported in the housing comprises a stator 22 secured to the bottom of depending upper housing elements 17 for ease of assembly and securement of parts and subassemblies in place in the pillars. An armature 24 is journalled in a front bearing block 35 for rotation in the stator and has a worm gear 26 and a fan 28 rotating in a shroud 30.

Two worm wheels 32 intermeshing with opposite sides of the worm gear 26 drive in opposite directions of rotation the sleeve shafts 34 journalled in a bearing block 35 (FIG. 3). The shafts 34 releasably receive the upper ends of conventional heaters to rotate them in opposite directions and interdigitate their blades in mixing operations. An inverted U shaped yoke member 36 carrying compression springs 38 on its legs 41 axially engage the upper ends of the beater shafts as at 40 (FIG. 3) to eject them downwardly when the yoke member 36 is forced downwardly. The yoke is actuated by an L-shaped member 42 whose foot 44 is disposed horizontally to interlock with a bail-like element 46 offof the L-shaped member extends upwardly through the fore pillar 18 of the food mixer to a level above the handle 12 where it receives a push button 52 for manual actuation. The yoke is supported upright by its legs telescoping in the beater drive sleeves 34 and the upright leg 50 is supported by the rotor 51 of the switch 54 which will now be described.

The switch 54 comprises an open sided box or frame member 55 of a molded plastic material whose ends 57 are notched at 53 to receive and journal at the bottoms thereof the ends 59 of a rotor 56 defining a plurality of circular and axially spaced cams 58 having one or more recesses 60 peripherally staggered so that no two coil switches are closed at the same time.

On a shelf 61 along one longitudinal wall 63 at one side of the rotor a stationary multiple contact bight portion 62 of a U-shaped switch element 64 is supported longitudinally where it is preferably open to external access within the open side 63 of the housing. The bight 62 lies flat on the shelf 61 and its leg ends extend through the shelf 61 and beyond the body as at 65 when inserted in place where they terminate and are locked in place when a connection 66 is soldered thereto as 2 selected number of switch blades 72, preferably plated with non-oxidizing highly conductive metal, can be located in selected castellations 71 with the free ends of the blades disposed to bridge across the rotor and cooperate as switch armatures 74 with the stationary contact 62. I

The switch armatures 74 are shown in FIGS. 5 -7. From the point where they extend from the castellation 71 they are provided with a V-shaped form that provides a cam-follower detent 76 between the switch contact end 78 thereof and the 'castellation 71. Over this length the switch is internally stressed to close the contact 78 and bear strongly against the rotor 56 at the detents 76. a

By way of withstanding this stress, the other end 80 of the switch blades 72 follows flatly along the outside face 82 of the housing, being apertured at 84 therealong to be received over rivet pins 86 formed integrally with the wall 70. The end 80 of the blades terminates adjacent to the back of the wall in a reverse closed loop 88 with the outer portion apertured at 90 to receive a bare wire 91 and the end edge 92 to press against the flat portion 93 to serve as a clamp lock for the wire end when it is pushed through the aperture 84 with the end forced between the flat body and the sharp end portion of the spring switch member to provide an electrical connection.

As shown in FIG. 3, the journals 53 are bifurcated at 83 into two opposing halves which permits the insertion of the rotor' whereby the radial pressure of the two halves can be frictionally increased against the rotor ends 57 when the braces 102 are secured in place with slight displacement towards each other by screws 103 as later described.

In the assembly, the stationary contact member 62 is pressed into place, the rotor 56 is snapped into the journals 53 that are slightly in excess of an 180 arc and the spring blades 72 are located in the castellations 71 on pins 86. Thereupon a comb-like member 94 is received on the pins 86 and fixture clamped for welding against the faces 82 of the switch members along the castellations.

The parallel teeth 96 of the comb assure parallel positioning and alignment of the spring members and a fixture (not shown) with detents coinciding with the apertures 84 are pressed heavily against the exterior of the comb as the plastic material in the pins 86 is either swaged under heat to rivet the spring members, or ultra-sonically welded to the housing wall 17 to hold the spring members in place. This riveting soldering of the materials permanently stress the spring contacts to close when their followers 76 coincide with the recesses 60 in the rotor.

Above the upper rotor journal 53 the hollow shaft of the rotor is radially flattened as at 97 to receive the corresponding rotationally mating contour on the hub 98 of a speed indicator dial 99 that is knurled peripherally at 100 and internally supports the push button 52 (FIG. 3). Thus the handle 12 protectively supports the speed dial 99 in journalled relation for speed selection which in turn supports the shaft 50 of the push rod 42 for easy and free beater ejection, it being available to the user to eject the beater as well as stop the motor in the usual course of usage or in an emergency.

At the lower end, appropriately shaped bracing legs 102 are formed or adhered integrally with the two bottom corners 104 of the switch frame 55 and are secured by screws 103 as shown in FIG. 2 to the top of the transmission block 35 and the bottoms of elements 17 to assure proper and easy assembly and support the switch body against rotation while also holding the push rod 42 in position.

In FIG. 7 a single recess 60 for each cam 58 and switch blade 72 is shown whereby a speed control switch 64 is closed at only one position of the dial 99.

In FIG. 6 dual cam recesses 60 are shown whereby switches can be permutated with others such as a switch 74A (FIG. 5) controlling a diode for a circuit as shown in FIG. 8. Accordingly, plural closure of field coil switches 74 can be permutated as more particularly described in Swanke Ser. No. 26,967 or one long recess such as 64A and a corresponding cam rise as shown in FIG. 5 can be employed to provide a combination with switch 74A (FIG. 6) two speeds, namely, by closing each switch once with switch 1 closed and once with switch 1 open for added speed versatility of selection.

By way of example circuitwise, there are shown three distinct field coil sections A, B and C of a stator 106 with color coded connections Y, G and B for sequential energization serially by switches 2, 3 and 4. Closure of switch 4 alone energizes coil A for a moderately high speed with half wave current; closure of switch 3 alone energizes coils A, Band C for the lowest speed of a low speed range. This sequence of switch closures can be repeated with the switch 1 closed to repeat the sequence for a higher speed range under full wave electrical power. Furthermore, such speed ranges can be reached in either sequence by movement of the dial in either one of both directions from OFF position.

Having thus described the present inventionand cercations can be made without departing from the inventive concept.

What is claimed is:

1. A switch for a food mixer comprising,

a housing open on one side and having two pairs of facing walls and a bottom wall,

a shelf along a wall of one pair and a stationary contact supported thereon having electrical terminals extending through the bottom wall,

a plurality of parallel resilient conductors supported on the outer side of the other wall of said one pair and terminally stressed at one end to engage said contact under pressure,

coaxial journals opening towards said conductors in the other pair of walls offset from said resilient conductors, and

rotor means journalled in said journals and including circumferential cam tracks engaging and selective ly holding a plurality of said switch conductors open under tension at any given time and said conductors holding said rotor means rotatably in place in said journals.

2. The switch defined in claim 1 in which said rotor is hollow and said mixer includes removable beaters,

a shaft reciprocable in the full length of said rotor to engage and release said beaters,

a speed control dial carried by said rotor and rotatively supporting said shaft for 360 rotation relative to said shaft.

3. The switch defined in claim 2, said mixer including a transmission block journalling said beaters,

said housing including two diverging depending leg means supporting said rotor and shaft against lateral movement with respect to the block, at least one of said journals being bifurcated into two opposing parts engaging said rotor means and movable towards each other by said two leg means when moved towards each other to establish friction upon said rotor means.

4. A switch for a multi-speed household appliance comprising,

a housing having a pair of facing walls,

a rotor between the walls including axially spaced circumferential cam tracks with circumferentially staggered restricted recesses for individual selection,

means for journalling the rotor at the ends of the walls over 180 of its circumference,

means for supporting an elongated stationary switch contact along one of the walls,

a plurality of elongated parallel resilient conductors supported intermediate their ends on the other of said walls with one end portion of each forming a detent to engage one of said recesses and terminating as a contact position to engage said switch contact, said end portion being stressed to normally engage said switch contact, some of said conductors being in open stressed engagement with said rotor at any given time to hold the rotor in said 6,. The switch defined in claim 4 including means of the same material as said other wall engaging said conductors intermediate their ends to hold them in place on the outer face of said other wall,

said conductors intermediate their ends being locally of different contour and embedded in said material integrated with the material of said other wall.

7. The switch defined in claim 4 including means interlocking said other wall and said supported intermediate portion, and

means holding said resilient conductors in parallel relationship.

8. The switch defined in claim 4 in which the other end of said conductor has an opening receiving a bare wire therethrough and is reversely curved upon itself with the terminal end thereof resiliently engaging said conductor under pressure for locking the bare wire in place therebetween.

9. The switch defined in claim 4 in which said stationary contact is a U-shaped strip of contact material whose legs extend through the one wall as a wire terminal connector means and the bight portion is engaged by said conductors as a common contact.

10. A switch for a multi-speed household appliance comprising,

a housing having a pair of facing walls,

a rotor between the walls including axially spaced circumferential cam tracks with circumferentially staggered restricted recesses for individual selection,

means for journalling the rotor at the ends of the walls over of its circumference in which at least one journal comprises spaced bearing sections of a circle,

means for supporting said bearing sections for frictionally tightening them against the end of said rotor,

means for supporting an elongated stationary switch contact along one of the walls,

a plurality of elongated parallel resilient conductors supported intermediate their ends on the other of said walls with one end portion of each forming a detent to engage one of said recesses and terminating'as a contact in position to engage said switch contact, said end portion being stressed to normally engage said switch contact and hold the rotor in said journalling means,

the other ends of said conductors receiving separate electrical connections to an electrical circuit.

1 1. A switch for a food mixer comprising,

a housing having two pairs of facing walls,

a shelf along a wall of one pair and a stationary contact supported thereon,

a plurality of parallel resilient conductors supported on the other wall of said one pair and terminally stressed at one end to engage said contact under pressure,

180 coaxial journal notches in the other pair of walls facing and offset from said resilient conductors, and

rotor means received radially in said notches to rest in said journals and having circumferential raised tracks selectively engaged by said conductors to hold a plurality of said switch conductors open at any given time under tension to hold said rotor means in said journals.

12. A speed control switch for a food mixer defined in claim 11 in which said rotor means is hollow and said mixer includes removable heaters,

a shaft extending through and reciprocable in said hollow of the rotor as supported in said journals to engage and release said beaters,

speed control dial carried by said rotor for 360 and movement rotatively supporting said shaft.

13. In a food mixer power unit having a transmission block journalling drive sleeves that receive removable beaters in drive relationship, a housing including a handle supporting the power unit by a hollow pillar at one end and defining a circular opening above said drive sleeves, the combination of manual switch control means joumalled in said circular opening,

a switch in said pillar including a switch housing having a pair of facing walls,

a rotor extending between the walls and having a plurality of axially spaced circumferential cam tracks collectively having circumferentially staggered restricted recesses,

laterally open means for journalling the walls and the rotor with respect to each other at said rotor ends,

said walls and rotor ends being supported concentrically with said circular opening at one of said rotor ends by said switch control means,

a plurality of elongated parallel resilient conductors supported on said switch housing transversely to and in contact with the rotor to hold the rotor in said joumalled relation with a portion of each conductor forming a detent to selectively engage said staggered recesses successively, said switch control means and rotor being concentrically hollow throughout their length,

said journalling means at the other end of said rotor including leg means interconnecting the switch housing and said transmission block to support said rotor against rotation and lateral movement with respect to said drive sleeves,

a beater ejector shaft means reciprocably mounted in said rotor and extending above said switch control means at one end and disposed coaxially at its other end with at least one of the drive sleeves to engage beaters present therein. 

1. A switch for a food mixer comprising, a housing open on one side and having two pairs of facing walls and a bottom wall, a shelf along a wall of one pair and a stationary contact supported thereon having electrical terminals extending through the bottom wall, a plurality of parallel resilient conductors supported on the outer side of the other wall of said one pair and terminally stressed at one end to engage said contact under pressure, coaxial journals opening towards said conductors in the other pair of walls offset from said resilient conductors, and rotor means journalled in said journals and including circumferential cam tracks engaging and selectively holding a plurality of said switch conductors open under tension at any given time and said conductors holding said rotor means rotatably in place in said journals.
 2. The switch defined in claim 1 in which said rotor is hollow and said mixer includes removable beaters, a shaft reciprocable in the full length of said rotor to engage and release said beaters, a speed control dial carried by said rotor and rotatively supporting said shaft for 360* rotatIon relative to said shaft.
 3. The switch defined in claim 2, said mixer including a transmission block journalling said beaters, said housing including two diverging depending leg means supporting said rotor and shaft against lateral movement with respect to the block, at least one of said journals being bifurcated into two opposing parts engaging said rotor means and movable towards each other by said two leg means when moved towards each other to establish friction upon said rotor means.
 4. A switch for a multi-speed household appliance comprising, a housing having a pair of facing walls, a rotor between the walls including axially spaced circumferential cam tracks with circumferentially staggered restricted recesses for individual selection, means for journalling the rotor at the ends of the walls over 180* of its circumference, means for supporting an elongated stationary switch contact along one of the walls, a plurality of elongated parallel resilient conductors supported intermediate their ends on the other of said walls with one end portion of each forming a detent to engage one of said recesses and terminating as a contact position to engage said switch contact, said end portion being stressed to normally engage said switch contact, some of said conductors being in open stressed engagement with said rotor at any given time to hold the rotor in said journalling means, the other ends of said conductors receiving separate electrical connections to an electrical circuit.
 5. The switch defined in claim 4 including means engaging said conductors intermediate their ends and securing them on the other side of said other wall.
 6. The switch defined in claim 4 including means of the same material as said other wall engaging said conductors intermediate their ends to hold them in place on the outer face of said other wall, said conductors intermediate their ends being locally of different contour and embedded in said material integrated with the material of said other wall.
 7. The switch defined in claim 4 including means interlocking said other wall and said supported intermediate portion, and means holding said resilient conductors in parallel relationship.
 8. The switch defined in claim 4 in which the other end of said conductor has an opening receiving a bare wire therethrough and is reversely curved upon itself with the terminal end thereof resiliently engaging said conductor under pressure for locking the bare wire in place therebetween.
 9. The switch defined in claim 4 in which said stationary contact is a U-shaped strip of contact material whose legs extend through the one wall as a wire terminal connector means and the bight portion is engaged by said conductors as a common contact.
 10. A switch for a multi-speed household appliance comprising, a housing having a pair of facing walls, a rotor between the walls including axially spaced circumferential cam tracks with circumferentially staggered restricted recesses for individual selection, means for journalling the rotor at the ends of the walls over 180* of its circumference in which at least one journal comprises spaced bearing sections of a circle, means for supporting said bearing sections for frictionally tightening them against the end of said rotor, means for supporting an elongated stationary switch contact along one of the walls, a plurality of elongated parallel resilient conductors supported intermediate their ends on the other of said walls with one end portion of each forming a detent to engage one of said recesses and terminating as a contact in position to engage said switch contact, said end portion being stressed to normally engage said switch contact and hold the rotor in said journalling means, the other ends of said conductors receiving separate electrical connections to an electrical circuit.
 11. A switch for a food mixer comprising, a housing having tWo pairs of facing walls, a shelf along a wall of one pair and a stationary contact supported thereon, a plurality of parallel resilient conductors supported on the other wall of said one pair and terminally stressed at one end to engage said contact under pressure, 180* coaxial journal notches in the other pair of walls facing and offset from said resilient conductors, and rotor means received radially in said notches to rest in said journals and having circumferential raised tracks selectively engaged by said conductors to hold a plurality of said switch conductors open at any given time under tension to hold said rotor means in said journals.
 12. A speed control switch for a food mixer defined in claim 11 in which said rotor means is hollow and said mixer includes removable beaters, a shaft extending through and reciprocable in said hollow of the rotor as supported in said journals to engage and release said beaters, speed control dial carried by said rotor for 360* and movement rotatively supporting said shaft.
 13. In a food mixer power unit having a transmission block journalling drive sleeves that receive removable beaters in drive relationship, a housing including a handle supporting the power unit by a hollow pillar at one end and defining a circular opening above said drive sleeves, the combination of manual switch control means journalled in said circular opening, a switch in said pillar including a switch housing having a pair of facing walls, a rotor extending between the walls and having a plurality of axially spaced circumferential cam tracks collectively having circumferentially staggered restricted recesses, laterally open means for journalling the walls and the rotor with respect to each other at said rotor ends, said walls and rotor ends being supported concentrically with said circular opening at one of said rotor ends by said switch control means, a plurality of elongated parallel resilient conductors supported on said switch housing transversely to and in contact with the rotor to hold the rotor in said journalled relation with a portion of each conductor forming a detent to selectively engage said staggered recesses successively, said switch control means and rotor being concentrically hollow throughout their length, said journalling means at the other end of said rotor including leg means interconnecting the switch housing and said transmission block to support said rotor against rotation and lateral movement with respect to said drive sleeves, a beater ejector shaft means reciprocably mounted in said rotor and extending above said switch control means at one end and disposed coaxially at its other end with at least one of the drive sleeves to engage beaters present therein. 